Extendable boom apparatus

ABSTRACT

An extendable boom apparatus having a first boom member pivotally secured to and supported by a frame. A second boom member is pivotally secured at one end thereof to one end of the first boom member and is adapted to fold jack-knife fashion to a position parallel to the second boom member and, alternately, to an extended position in axial alignment with the second boom member. The alternate folding and extending of the apparatus is accomplished by means of a drive wheel, mounted on a transverse power driven shaft journaled in the end of the first boom member adjacent the second boom member, whose periphery is meshingly engaged with the arcuately shaped periphery of a plate fixedly secured to the second boom member. Apparatus is also disclosed which permits the drive wheel to be disengaged from the shaft so that the shaft is free to rotate within the drive wheel without imparting rotary motion thereto and thereby permitting the power driven shaft to be used for winch purposes.

United States Patent 1191 Ballard [451 May 15, 1973 [5 4] EXTENDABLEBOOM APPARATUS [76] Inventor: Donald R. Ballard, Route 1 Box 310A,Sapulpa, Okla.

[22] Filed: Mar. 12,1971

[21] Appl. No.: 123,770

52 use! ..74/89.18,182/2 51 lnt.Cl ..Fl6h27/02 [58] FieldofSearch..74/89.18,422,89.17,

[56] References Cited UNITED STATES PATENTS 3,610,058 7/1969 Mueller etal. ..74/89.17

509,665 11/1893 Jaquette 1 ..74/89.l8 3,289,695 12/1966 Thomaset al.........74/89.18

2,500,815 3/1950 Gerli ..l82/2 2,616,768 11/1952 Stemm r ..l82/22,988,163 6/1961 Foley ..l82/2 Primary Examiner-Allan D. HerrmannAssistant Examiner-Wesley S. Ratliff, Jr. Attorney- Dunlp, Laney, Hessin& Dougherty w I i 4a a 9f 1 70 [57] ABSTRACT An extendable boomapparatus having a first boom member pivotally secured to and supportedby a frame. A second boom member is pivotally secured at one end thereofto one end of the first boom member and is adapted to fold jack-knifefashion to a position parallel to the second boom member and,alternately, to an extended position in axial alignment with the secondboom member. The alternate folding and extending of the apparatus isaccomplished by means of a drive wheel, mounted on a transverse powerdriven shaft journaled in the end of the first boom member adjacent thesecond boom member, whose periphery is meshingly engaged with thearcuately shaped periphery of a plate fixedly secured to the second boommember. Apparatus is also disclosed which permits the drive wheel to bedisengaged from the shaft so that the shaft is free to rotate within thedrive wheel without imparting rotary motion thereto and therebypermitting the power driven shaft to be used for winch purposes.

11 Claims, 8 Drawing Figures 70 O y y 1 EXTENDABLE BOOM APPARATUSBACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates generally to improvements in extendable booms and moreparticularly, but not by way of limitation to extendable booms used ontruckmounted derricks for supporting workmens baskets and the like.

2. Description of the Prior Art The prior art discloses numerous schemesfor mechanically extending derrick boom members. Generally these schemesrequire somewhat elaborate and expensive linkages and separate powersources or power take-offs. The prior art also discloses somewhat lessexpensive derrick structures which utilize manual effort to extend andfold the boom extensions attached thereto.

SUMMARY OF THE INVENTION The present invention defines an extendableboom apparatus which includes a base, and a first boom member, having afirst end portion and second end portion, the first boom member beingpivotally secured at the first end portion thereof to the base. A secondboom member, having a first end portion and a second end portion, ispivotally secured at the first end portion thereof to the second endportion of the first boom member and is adapted to pivot to ajack-knifeposition adjacent and substantially parallel to the first boom memberand, alternately, to pivot to an extended position in generally axialalignment with the first boom member. A shaft, having a first endportion and a second end portion, is transversely journaled in thesecond end portion of the first boom member. Rotating means is connectedto the first end portion of the shaft for rotating the shaft. A drivewheel is secured to the second rotation of the shaft and drive wheelsecured thereto in one direction causes a resultant rotation of theplate in the opposite direction thereby pivoting the second boom memberfrom the jack-knife position to the extended position and, alternately,from the extended position to the jack-knife position.

An object of the present inventionis to provide an improved extendableboom apparatus for use on derrick structures.

Another object of the present invention is to provide an extendable boomapparatus for modifying a derrick structure having a manually extendableboom so that the boom may be extended mechanically without manualeffort.

A further object of the present invention is to provide an extendableboom apparatus, which may be simply and easily installed in the field,for modifying a derrick structure having a manually extendable boom sothat the boom may be extended mechanically without manual effort.

A still further object of the present invention is to provide anextendable boom apparatus which derives its power from the boom tipwinch.

Another object of the present invention is to provide an extendable boomapparatus which is economical in construction and operation.

Other objects and advantages of the present invention will be evidentfrom the following detailed description when read in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation viewillustrating the apparatus of the present invention in the foldedjack-knife position.

FIG. 2 is a side elevation view illustrating the apparatus of thepresent invention in the extended position.

FIG. 3 is a schematic end view taken along lines 3-3 of FIG. 1, withportions of the second boom member broken away, more clearlyillustrating the apparatus of the present invention.

FIG. 4 is a fragmentary side elevation view more clearly illustratingapparatus of the present invention in the extended position.

FIG. 5 is a fragmentary view taken along lines 55 of FIG. 4.

FIG. 6 is a fragmentary view similar to FIG. 5 illustrating an alternateembodiment of the present invention.

FIG. 7 is a fragmentary side elevation view similar to FIG. 4illustrating another embodiment of the present invention.

FIG. 8 is a fragmentary view taken along lines 8-8 of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1, 2, 3,4 and 5, and particularly to FIGS. 1 and 2, the apparatus of the presentinvention is generally designated by reference character 10. Theapparatus 10 comprises a vehicle 12 such as a truck and an extendableboom 14 carried by the vehicle 12. The extendable boom 14 comprises abase 16 which is pivotally secured to the rear end 18 of the truck 12,and is adapted to pivot thereon about a vertical axis. A first boommember 20 is pivotally secured at the first end portion 22 thereof tothe base 16 by pin connection 24, and is adapted to pivot thereon abouta horizontal axis. A power cylinder 26 is pivotally secured at the firstend 28 thereof to the base 16 by pin connection 30 and is pivotallysecured at the second end 32 thereof to the lower medial portion 34 ofthe first boom member 20 by pin connection 36.

A shaft 38 is mounted transversely in the upper portion of the secondend 40 of the first boom member 20. A second shaft 42 is transverselymounted in the lower portion of the second end 40 of the first boommember 20. A power driven boom tip winch 44 is mounted transversely onthe second end 40 of the first boom member 20.

The power driven boom tip winch 44 comprises generally a winch drivemotor 46 carried on one side of the first boom member 20, a winch shaft48 transversely journaled in the second end 40 of the first boom member20 and connected at the first end 49 thereof to the winch drive motor46, and a winch reel 50 rigidly secured to the winch shaft 48. A winchline 52 is carried on the winch reel 50. The second end 54 of the winchshaft 48 extends a substantial distance beyond the first boom member 20on the side opposite the winch drive motor 46. A hole 56 is formed inthe winch shaft 48 normal to the axis thereof near the end 54 of thewinch shaft 48. A hub 58 is carried on the winch shaft 48 adjacent theend 54 thereof. The hub 58 is sized such that it is free to rotate onthe winch shaft 48. Two holes 60 are formed in the hub 58 in axialalignment normal to the axis of rotation of the hub 58. The holes 56 and60 are sized and positioned in the respective winch shaft 48 and hub 58such that a locking pin 62 may be simultaneously passed through theholes 56 and 60 thereby locking the hub 58 to the winch shaft 48 forrotation therewith. A double chain drive sprocket 64 is fixedly securedto the hub 58.

A second boom member. 66 comprises a boom section 68, a boot 70 fixedlysecured to the first end portion 72 of the boom section 68, and apersonnel bucket pivot shaft 74 carried by the boom section 68 adjacentthe second end portion 76 of the boom section 68. Two hinge brackets 78and two boom support legs 80 are formed on the boot 70.

The second boom member 66 is pivotally secured to the first boom member20 by means of the two hinge brackets 78 which are journaled on theshaft 38 of the first boom member 20, and is adapted to pivot thereonabout a horizontal axis. The second boom member 66 is adapted to pivotfrom a folded jack-knife position substantially parallel to the firstboom member 20 to an extended position in substantial axial alignmentwith the second boom member 20. As illustrated in FIG. 4, when thesecond boom member 66 is in the extended position, the boom support legs80) bear on the second shaft 42 of the first boom member 20. A lockingpin 82 may be inserted through a hole 84 formed in the second end 40 ofthe first boom member 20 to retain the second boom member 66 in theextended position.

A plate 86 is fixedly secured to the boot 70 by four bolts 88. The plate86 is spaced away from the boot 70 by four spacers 90 carried on therespective bolts 88. The plate 86 has an arcuately shaped peripheralportion 92. The are of the arcuately shaped peripheral portion 92 of theplate 86 is swung from the point of intersection of the plane of theplate 86 and the axial centerline of the shaft 38. A double drive chain94 is welded to the arcuately shaped peripheral portion 92 of the plate86. The pitch of the double drive chain 94 is identical to the pitch ofthe double chain drive sprocket 64. The double chain drive sprocket 64is continuously meshingly engaged with the double drive chain 94.

A personnel bucket 96 is carried by the personnel bucket pivot shaft 74near the second end portion 76 of the boom section 68. The personnelbucket 96 is carried by the personnel bucket pivot shaft 74 in a pendantposition regardless of the position of the second boom member 66.

OPERATION OF THE PREFERRED EMBODIMENT To extend the second boom member66 from its folded position as shown in FIG. 1, the power driven boomtip winch 44 is operated to lower the winch line 52 approximately 24inches to 30 inches. The locking pin 62 is inserted through the holes 60in the hub 58 and the hole 56 in the winch shaft 48. The hub 58 is thenrigidly secured to the winch shaft 48. The power driven boom tip winch44 is then operated in the opposite direction to raise the winch line 52and at the same time rotate the hub 58 and the double chain drivesprocket 64 secured thereto in a clockwise direction, as

viewed in FIG. 1. The clockwise rotation of the double sprocket 64causes a resulting counterclockwise rotation of the second boom member66 about the shaft 38 through the meshing engagement of the double chaindrive sprocket 64 with the double drive chain 94 mounted on the plate86.

When the second boom member 66 has reached the fully extended position,as shown in FIGS. 2 and 4, the boom support legs 80 abut the secondshaft 42. At this time, the power driven boom tip winch 44 is shut off.If it is desired to use the power driven boom tip winch 44 while thesecond boom member 66 is fully extended, the locking pin 82 should beinserted in the hole 84, thereby securing the second boom member 66 inthe fully extended position. See FIG. 4. The locking pin 62 should thenbe removed from the winch shaft 48 and the hub 58, thereby allowing thewinch shaft 48 to rotate freely within the hub 58 when the winch line 52is raised or lowered.

To return the second boom member 66 from the extended position, as shownin FIG. 2, to the folded position, as shown in FIG. 1, the power drivenboom tip winch 44 should be activated to raise the winch line 52 up tothe reel 50. The locking pin 62 should again be inserted into the holes60 in the hub 58 and the hole 56 in the winch shaft 48 thereby lockingthe hub 58 to the winch shaft 48. The locking pin 82 is then removedfrom the hole 84. The power driven boom tip winch 44 is then activatedto lower the winch line 52 which in turn rotates the double chain drivesprocket 64 in the counterclockwise direction as viewed in FIG. 2. Thecounterclockwise rotation of the double chain drive sprocket 64 resultsin the clockwise rotation of the second boom member 66 about the shaft38. When the second boom member 66 reaches the folded position,substantially parallel to the first boom member 20, the power drivenboom tip winch 44 is shut off.

It should be noted that'if the power driven winch 44 is not to be usedwhen the second boom member 66 is in its fully extended position, thelocking pin 62 need not be removed from the hub 58 and the winch shaft48, and the locking pin 82 need not be inserted in the hole 84 in thesecond end portion 40 of the first boom member 20.

DESCRIPTION OF THE EMBODIMENT OF FIG. 6

The apparatus illustrated in FIG. 6 is identical to the apparatuspreviously described for the preferred embodiment except that a singlechain drive sprocket 98 is formed on the hub 58 which continuously andmeshingly engages a single drive chain 100 which is welded to the plate86. The apparatus of FIG. 6 finds application when the second boommember 66 is lightly loaded such as when no personnel bucket 96 is to beused therewith. The operation of the apparatus illustrated in FIG. 6 isidentical to that described above for the preferred embodiment.

DESCRIPTION OF THE APPARATUS OF FIGS. 7 and 8 The apparatus of FIGS. 7and 8 is identical to the apparatus previously described for thepreferred embodiment except that instead of a double chain drivesprocket 64, a pinion gear 102 is carried by the hub 58 and is rigidlysecured thereto. Gear teeth 104 are formed on the arcuately shapedperipheral portion 92 of the plate 86 and continuously and meshinglyengage the teeth of the spur gear 102. The operation of the apparatusillustrated in FIGS. 7 and 8 is identical to that described above forthe preferred embodiment.

From the foregoing, it will be apparent that the present inventionprovides an extendable boom apparatus which utilizes a power driven boomtip winch to extend and retract a previously manually extendable boom sothat the boom may be extended without manual effort.

Changes may be made in the combination and arrangement of parts orelements as heretofore set forth in the specification and shown in thedrawing without departing from the spirit and scope of the invention.

What is claimed is:

1. An extendable boom apparatus, comprising:

a base;

a first boom member, having a first end portion and a second endportion, said first boom member being pivotally secured at the first endportion thereof to said base;

a second boom member having a first end portion and a second endportion, said first end portion thereof being pivotally secured to thesecond end portion of the first boom member and being adapted to pivotto a folded jack-knife position adjacent and substantially parallel tothe first boom member and, alternately, to pivot to an extended positionin substantial axial alignment with the first boom member;

shaft means, having a first end portion and a second end portion,transversely journaled in the second end portion of the first boommember for rotating therein;

a drive wheel carried on the second end portion of the shaft means;

connecting means for securing the drive wheel to the second end portionof the shaft means for rotation therewith;

a plate fixedly secured to the first end portion of the second boommember, a portion of the periphery of the plate being arcuately shapedand continuously meshingly engaging the periphery of the drive wheel;and

drive means connected to the first end portion of the shaft means fordrivingly rotating the shaft means and drive wheel secured thereto inone direction thereby drivingly rotating the plate in the oppositedirection whereby the second boom member is pivoted from the foldedjack-knife position to the extended position and, alternately, from theextended position to the folded jack-knife position.

2. An extendable boom apparatus as defined in claim 1 wherein the drivewheel may be disengaged from the shaft means so that the shaft means maybe rotated independently without rotating the drive wheel.

3. An extendable boom apparatus as defined in claim 2 wherein the shaftmeans is a winch shaft.

4. An extendable boom apparatus as defined in claim 1 wherein the drivewheel is a chain drive sprocket and the arcuately shaped peripheralportion of the plate has a drive chain formed thereon which is meshinglyengaged with the chain drive sprocket.

5. An extendable boom apparatus as defined in claim I wherein the drivewheel is a double chain drive sprocket and a double drive chain isformed on the arcuately shaped peripheral portion of the plate and ismeshingly engaged with the double chain drive sprocket.

6. An extendable boom apparatus as defined in claim 1 wherein the drivewheel is a pinion gear and gear teeth are formed on the arcuately shapedperipheral portion of the plate, the pinion gear being continuouslymeshingly engaged with the gear teeth on the plate.

7. In combination with a truck-mounted extendable boom apparatus of thetype wherein a base is pivotally mounted on the rear portion of a truckand is adapted to pivot about a vertical axis; a first boom member,having a first end portion and a second end portion, is pivotallysecured at the first end portion thereof to said base and is adapted topivot thereon about a horizontal axis; a second boom member, having afirst end portion and a second end portion, is pivotally secured at thefirst end portion thereof to the second end portion of the first boommember and is adapted to pivot thereon about a horizontal axis to afolded jack-knife position adjacent and substantially parallel to thefirst boom member and, alternately, to pivot to an extended posi' tionin substantial axial alignment with the first boom member; a winchshaft, havinga first end portion and a second end portion, istransversely journaled in the second end portion of the first boommember with the second end portion of the winch shaft extendingoutwardly therefrom; and drive means is connected to the first endportion of the winch shaft for rotation thereof; the improvementcomprising:

a drive wheel carried on the second end portion of the winch shaft;

a plate fixedly secured to the first end portion of the second boommember, a portion of the periphery of the plate being arcuately shapedand continuously meshingly engaging the periphery of the drive wheel;and

connecting means for securing the drive wheel to the second end portionof the winch shaft so that driving rotation of the winch shaft and drivewheel secured thereto by the drive means in one direction therebydrivingly rotates the plate in the opposite direction whereby the secondboom member is pivoted from the folded jack-knife position to theextended position, and, alternately, from the extended position to thefolded jack-knife position.

8. An improved extendable boom apparatus as defined in claim 7 whereinthe drive wheel may be disengaged from the winch shaft so that the winchshaft may be rotated independently without rotating the drive wheel.

9. An improved extendable boom apparatus as defined in claim 7 whereinthe drive wheel is a chain drive sprocket and the arcuately shapedperipheral portion of the plate has a drive chain formed thereon whichis meshingly engaged with the chain drive sprocket.

10. An improved extendable boom apparatus as defined in claim 7 whereinthe drive wheel is a double chain drive sprocket and a double drivechain is formed on the arcuately shaped peripheral portion of the plateand is meshingly engaged with the double chain drive sprocket.

11. An improved extendable boom apparatus as defined in claim 7 whereinthe drive wheel is a pinion gear and gear teeth are formed on thearcuately shaped peripheral portion of the plate, the pinion gear beingcontinuously meshingly engaged with the gear teeth on the plate. I

1. An extendable boom apparatus, comprising: a base; a first boommember, having a first end portion and a second end portion, said firstboom member being pivotally secured at the first end portion thereof tosaid base; a second boom member having a first end portion and a secondend portion, said first end portion thereof being pivotally secured tothe second end portion of the first boom member and being adapted topivot to a folded jack-knife position adjacent and substantiallyparallel to the first boom member and, alternately, to pivot to anextended position in substantial axial alignment with the first boommember; shaft means, having a first end portion and a second endportion, transversely journaled in the second end portion of the firstboom member for rotating therein; a drive wheel carried on the secondend portion of the shaft means; connecting means for securing the drivewheel to the seconD end portion of the shaft means for rotationtherewith; a plate fixedly secured to the first end portion of thesecond boom member, a portion of the periphery of the plate beingarcuately shaped and continuously meshingly engaging the periphery ofthe drive wheel; and drive means connected to the first end portion ofthe shaft means for drivingly rotating the shaft means and drive wheelsecured thereto in one direction thereby drivingly rotating the plate inthe opposite direction whereby the second boom member is pivoted fromthe folded jack-knife position to the extended position and,alternately, from the extended position to the folded jack-knifeposition.
 2. An extendable boom apparatus as defined in claim 1 whereinthe drive wheel may be disengaged from the shaft means so that the shaftmeans may be rotated independently without rotating the drive wheel. 3.An extendable boom apparatus as defined in claim 2 wherein the shaftmeans is a winch shaft.
 4. An extendable boom apparatus as defined inclaim 1 wherein the drive wheel is a chain drive sprocket and thearcuately shaped peripheral portion of the plate has a drive chainformed thereon which is meshingly engaged with the chain drive sprocket.5. An extendable boom apparatus as defined in claim 1 wherein the drivewheel is a double chain drive sprocket and a double drive chain isformed on the arcuately shaped peripheral portion of the plate and ismeshingly engaged with the double chain drive sprocket.
 6. An extendableboom apparatus as defined in claim 1 wherein the drive wheel is a piniongear and gear teeth are formed on the arcuately shaped peripheralportion of the plate, the pinion gear being continuously meshinglyengaged with the gear teeth on the plate.
 7. In combination with atruck-mounted extendable boom apparatus of the type wherein a base ispivotally mounted on the rear portion of a truck and is adapted to pivotabout a vertical axis; a first boom member, having a first end portionand a second end portion, is pivotally secured at the first end portionthereof to said base and is adapted to pivot thereon about a horizontalaxis; a second boom member, having a first end portion and a second endportion, is pivotally secured at the first end portion thereof to thesecond end portion of the first boom member and is adapted to pivotthereon about a horizontal axis to a folded jack-knife position adjacentand substantially parallel to the first boom member and, alternately, topivot to an extended position in substantial axial alignment with thefirst boom member; a winch shaft, having a first end portion and asecond end portion, is transversely journaled in the second end portionof the first boom member with the second end portion of the winch shaftextending outwardly therefrom; and drive means is connected to the firstend portion of the winch shaft for rotation thereof; the improvementcomprising: a drive wheel carried on the second end portion of the winchshaft; a plate fixedly secured to the first end portion of the secondboom member, a portion of the periphery of the plate being arcuatelyshaped and continuously meshingly engaging the periphery of the drivewheel; and connecting means for securing the drive wheel to the secondend portion of the winch shaft so that driving rotation of the winchshaft and drive wheel secured thereto by the drive means in onedirection thereby drivingly rotates the plate in the opposite directionwhereby the second boom member is pivoted from the folded jack-knifeposition to the extended position, and, alternately, from the extendedposition to the folded jack-knife position.
 8. An improved extendableboom apparatus as defined in claim 7 wherein the drive wheel may bedisengaged from the winch shaft so that the winch shaft may be rotatedindependently without rotating the drive wheel.
 9. An improvedextendable boom apparatus as defined in claim 7 wherein the drive wheelis a chain drive sprocket and the arcUately shaped peripheral portion ofthe plate has a drive chain formed thereon which is meshingly engagedwith the chain drive sprocket.
 10. An improved extendable boom apparatusas defined in claim 7 wherein the drive wheel is a double chain drivesprocket and a double drive chain is formed on the arcuately shapedperipheral portion of the plate and is meshingly engaged with the doublechain drive sprocket.
 11. An improved extendable boom apparatus asdefined in claim 7 wherein the drive wheel is a pinion gear and gearteeth are formed on the arcuately shaped peripheral portion of theplate, the pinion gear being continuously meshingly engaged with thegear teeth on the plate.